The present invention relates to the operation of decoys against threats and to Electronic Counter Measures, and more specifically to a counter measure utilizing an expendable autonomous airborne vehicle.
Since the last decades, fighting ships are equipped with Electronic Warfare Systems (EWS) and with Radar Counter Measures (RCMs) as a protection against incoming threats such as guided missiles. The significance of the threat imposed by pinpoint precision weapon systems aimed against naval units was vividly demonstrated during the Falkland War. On May 4, 1982, the HMS Sheffield was hit by an AM-39 Exocet missile launched by an Argentine Super-Etendard. After fighting the fire for more than five hours, the ship was abandoned and sank six days later when being towed. A total of 20 crewmen died and 24 were injured. Special attention is therefore wisely devoted to protection against radar-guided missiles and to missiles with radar seekers.
Previous inventions present insight about the state of the art. Canadian Patent No. 1238400, to Arunas Macikunas et al., divulges a land based radar reflector for use in maritime navigation systems. Such passive radar reflectors for navigation in inland waterways, lakes, harbors and the like, are not the intention of the present disclosure.
British Patent No. 2189079, to Barry J. James et al., discloses a passive defense implemented as a floatable decoy that includes an inflatable framework or cage, operative with radar reflective panels. Another floating device, available on the market as IDS 300, is made by Irvin Aerospace Ltd., of Icknield Way, Letchworth, Hertfordshire, Great Britain SG6 1 EU, which sells a naval decoy, set to sea from a ship""s deck. It should be considered that at sea, the waves shield the floating decoy from the sight of an incoming enemy threat, whereby the decoy features degraded effectiveness. Moreover, the floating decoy is thrown overboard, thus close to the ship, making it impossible to open a range between the decoy and the ship from the beginning.
Still another version of passive defense RCM is chaff, as described in xe2x80x9cAdvances in Passive Expendable Countermeasuresxe2x80x9d, by Vic Pheasant in the Journal of Electronic Defense, pp. 41-46, May 1998, and in Anti-Ship Missiles (ASM) and Countermeasures (Part II ASMD), published in Naval Forces, February 2001. Chaff is known since World War II, and is in common use with many naval forces all over the world. Such chaff-dispensing systems are made and sold by Rafael, Armament Development Authority Ltd., Israel, for more than twenty years. These chaff-rockets usually disperse chaff to form a cloud of large dimensions. Nowadays, puffs of chaff are expected to deceive but a decreasing number of seekers equipping modern Anti-Ship Missiles.
However, none of the previously known devices permits to provide complete simulation of a ship. None of them fly a single point RCM on-board of an expendable airborne vehicle for release in mid-air, at a predetermined point, to effectively simulate a target and to thwart an expected or incoming airborne radar threat. The previously mentioned inventions are not configured to counter an incoming radar-homing missile at ranges spanning from great distance to close proximity from the platform to be protected, by a self-erecting single point decoy. Furthermore, these known inventions do not provide threat-alluring decoys for release in mid-air as a single point RCM arranged for self-erection and deployment at a precisely determined point in the sky.
There is thus a widely recognized need for, and it would be highly advantageous to have, an inexpensive RCM operating a quick reaction system, launching an expendable airborne vehicle for the deployment of a self-erecting corner radar decoy structure, as a single point decoy. It is also desirable for the point decoy to feature a large radar cross section, RCS, to effectively simulate a huge target, such as a ship, to achieve luring the enemy away from the real target. In addition, it would be an advantage to deploy the expendable decoy at a predetermined point in mid-air, away from the attacked platform.
It is an object of the present invention to provide a quick response means for fast reaction to an impending or actual threat using radar.
Another object of the present invention is to provide a point decoy featuring a large radar cross-section, or RCS, effectively simulating a large target.
It is a further object of the present invention to provide an expendable point decoy storable and transportable while kept folded in a minimum space and self-erecting when released.
Yet, another object of the present invention is to provide an autonomous expendable airborne Radar Counter Measure system (RCMS) for protection from a threat guided by or operating in association with radar signals. The RCMS comprises a launching system mounted on a platform, and an airborne vehicle launched in predetermined trajectory by the launching system. The airborne vehicle carries a payload comprising at least one CRC (Corner Reflector Construction) that when deployed, is operationally effective for deception of the threat. The airborne vehicle further comprises a release system for releasing the at least one CRC from the airborne vehicle at a predetermined point P, and a self-erection system for deploying the at least one CRC.
Still another object of the present invention is to provide a control system for management and operation of the RCMS, the control system being selected, alone and in combination, from the group consisting of centralized and distributed control systems. The RCMS has at least one controller to provide management and operation of airborne vehicle functions. Moreover, management and operation of functions of the airborne vehicle, of the release system and of the self-erection system are performed by at least one controller.
An additional object of the present invention is to provide a platform selected from a group consisting of airborne, waterborne, and ground-borne platforms. The platform is thus possibly a marine platform.
One more object of the invention is to provide an airborne vehicle launched in either one of two operating modes comprising firing from an artillery piece and launching as a self-propelled vehicle. Preferably, the airborne vehicle is configured for launch by a rocket motor.
Furthermore, it is an object of the present invention to provide for the release of each one of the at least one CRC, respectively, at one predetermined point P on the trajectory of the airborne vehicle. The predetermined release point P is selected, alone and in combination, from the group consisting of points in space, points in time and points of altitude. Possibly, each one of the at least one CRC is released at one predetermined point P in time.
There is also provided as an object of the present invention at least one CRC configured to deploy by self-erection of at least one radar reflector to reflect radar signals. The at least one CRC provides a predetermined Radar Cross Section (RCS) when deployed, and comprises at least one multi-directional radar corner reflector, or at least one trihedral radar corner reflector. Preferably, the multi directional radar reflector comprises eight trihedral radar corner reflectors.
It is also an object of the present invention to provided for the at least one CRC to self-erect by application of elastic forces inherent therewithin, or of inflation pressure, or of aerodynamic forces derived from the predetermined trajectory, or of forces derived on-board the airborne vehicle. Possibly, the at least one CRC self-erects by forces derived from pyrotechnic means, or by forces derived from the release system, or by inertia forces, or by forces derived from the environment, or by a combination of forces.
Another object of the present invention is to provide a method of operation of a Quick Response Counter Measure (QRCM) against an airborne radar threat. The method comprising the steps of detecting a radar-guided threat, responding to the detected threat by launching, from a platform, and into predetermined trajectory, of an expendable autonomous airborne vehicle. The airborne vehicle comprises a payload with at least one CRC, that when self-erected, is configured for deception of the radar-guided threat, for flying the payload to a predetermined point of release, for releasing the at least one CRC from the airborne vehicle, and for deploying the at least one CRC to start deception.
It is a further object of the present invention to provide a method for managing and operating the QRCM by a control system selected, alone and in combination, from the group consisting of centralized and distributed control systems. The control system comprises at least one controller to provide management and operation of airborne vehicle functions. Furthermore, management and operation of functions of the airborne vehicle, of the payload release system and of the payload inflation system are performed by at least one controller.
Yet, another object of the present invention is to provide a method wherein the platform comprises airborne, waterborne, and ground-borne platforms. Possibly, the airborne vehicle is launched from a marine platform.
Still another object of the present invention is to provide a method for launching the airborne vehicle that comprises firing the airborne vehicle from an artillery piece and launching thereof as a self-propelled vehicle. The airborne vehicle is preferably configured for launch by a rocket motor.
One more object of the invention is to provide a method comprising the releasing of each one of the at least one CRC, respectively, at one predetermined point P on the trajectory of the airborne vehicle. That predetermined release point P is selected, alone and in combination, from the group consisting of points in space, points in time and points of altitude. Possibly, the at least one CRC is released at one predetermined point P in time.
An additional object of the present invention is to provide a method wherein the at least one CRC is configured to deploy by self-erection of at least one radar reflector to reflect radar signals. When deployed, the at least one CRC is configured to provide a predetermined Radar Cross Section (RCS), and the at least one CRC comprises at least one multi-directional radar corner reflector or at least one trihedral radar corner reflector. Preferably, the multi-directional radar reflector comprises eight trihedral radar corner reflectors.
Furthermore, it is an object of the present invention to provide a method for the at least one CRC to self-erect by application of elastic forces inherent therewithin, or of inflation pressure, or of aerodynamic forces derived from the predetermined trajectory, or of forces derived on-board the airborne vehicle. Possibly, the method comprises at least one CRC that self-erects by forces derived from pyrotechnic means, or by forces derived from the release system, or by inertia forces, or by forces derived from the environment, or by a combination of forces.